1. Field of the Invention
The present invention relates to a curable silicone resin composition which is useful as a material for optical devices or parts, insulation material for electronic devices or parts, or coating material.
2. Description of the Prior Art
Conventionally, epoxy resins have been generally used as a material for optical devices or parts, in particular, sealing material for light emitting diode (LED) elements. In addition, it has been attempted to use a silicone resin as a molding material for LED elements (see Patent Documents 1 and 2) and also to use it as a color filter material (see Patent Document 3). However, examples of practical applications are few.
Recently, under circumstances where white LEDs are paid attention to, problems, which were not subjects of discussion before, such as yellowing of an epoxy sealing material caused by ultraviolet rays or cracking caused by increase of heat generation associated with downsizing of the white LEDs have occurred and solution is sought urgently. To address these problems, use of a cured product of a silicone resin with a number of phenyl groups is examined. Meanwhile, LED light sources which emit light with a shorter wavelength tend to be used presently. However, since epoxy sealing materials and phenyl group-containing silicone resin sealing materials have poor optical transmission in the short wavelength region, they are unsuitable to be applied to LEDs which emit light in the short wavelength region.
Patent Document 1: Japanese Laid-open Patent publication (kokai) No. Hei 10-228249 (JP10-228249A)
Patent Document 2: Japanese Laid-open Patent publication (kokai) No. Hei 10-242513 (JP10-242513A)
Patent Document 3: Japanese Laid-open Patent publication (kokai) No. 2000-123981 (JP2000-123981A)